Differential Expression of E- Cadherin and P-Cadherin in Breast Cancer Molecular Subtypes

Background/Aim: E- and P-cadherin (E-cadh, P-cadh) control tumor cell invasion, metastatic or stemness potential and chemotherapy resistance. The study aimed to assess E- and P-cadherin expression in breast cancer molecular subtypes. Materials and Methods: Immunohistochemistry for E-cadh and P-cadh was performed for 97 breast cancer cases. Membrane (M), cytoplasmic (C) or mixed (MC) patterns of E-cadh and P-cadh were considered in our evaluation. Results: E-cadh and P-cadh C pattern was significantly correlated in the HER2 subtype (p=0.031). P-cadh M pattern was highly specific for the HER2 subtype (p=0.002). Only P-cadh C characterized the triple negative breast cancer subtype (p=0.015). For Luminal B/HER2 cases, P-cadh M pattern was strongly coexpressed with the E-cadh MC pattern (p=0.012). Progesterone receptor (PR) expression influenced E-cadh M pattern in the Luminal B/HER2 subtype (p=0.042). Conclusion: E- and P- cadherins define distinct subgroups within breast cancer molecular subtypes. Our findings support the inclusion of E- and P-cadherin into breast cancer molecular classification.